This invention concerns a tool for use in deep water, which tool consists of or includes a sealing device.
Such a tool, with a sealing device, may be used for recovery of pipelines from such great depths that all work has to be carried out by remotely operated vehicles, as opposed to divers. A number of known tools of this type use hydraulic pressure to operate the sealing device, whereby the tool fastens itself to a pipe section, for hauling same back to the surface. Obviously, these tools rely on having a hydraulic line from the surface to the tool, which may be on the sea bed.
An object of the present invention is to obviate the need for such a hydraulic line.
According to the present invention, in a sealing device of an underwater tool, external water pressure at depth can act on a piston, which is movable within a chamber, to cause it to compress a seal member.